Bug 548876 (CVE-2009-4271)

Summary: CVE-2009-4271 kernel: 32bit process on 64bit system can trigger a kernel panic
Product: [Other] Security Response Reporter: Vincent Danen <vdanen>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: amwang, anton, dhoward, iannis, jlieskov, jolsa, jskrabal, lgoncalv, lwang, raud, security-response-team, tao, vgoyal, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2013-03-15 04:01:05 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 549230, 549231    
Bug Blocks:    

Description Vincent Danen 2009-12-18 22:32:48 UTC
A flaw was reported in the Linux kernel, versions 2.6.9 to 2.6.17, when running on x86_64, where a user could use a regular 32bit process to trigger a kernel panic, without any special privileges.  The bug occurs when a 32bit user process triggers a segfault (i.e. de-reference a null-pointer) after having performed a mprotect() to restrict any rwx access on its VDSO page.

In version 2.6.18 and on, the internal mechanism to access the VDSO uses the find_vma() wrapper which fixes the problem as a side-effect.

The reporter indicates that this only occurs on a 64bit machine with a program compiled in 32bit mode.


Red Hat would like to thank STMicroelectronics for responsibly reporting this issue.

Comment 14 errata-xmlrpc 2010-03-17 00:46:55 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 4

Via RHSA-2010:0146 https://rhn.redhat.com/errata/RHSA-2010-0146.html